Hi Janusz Majewski,
Based on the behavior you described, it appears that the update may have modified certain network discovery or SMB related components, which can occasionally impact visibility of devices on the local network. As a first step, I recommend ensuring that the Function Discovery Provider Host and Function Discovery Resource Publication services are running and set to Automatic (Delayed Start), as these are required for network discovery to function correctly. Additionally, please verify that Network Discovery and File and Printer Sharing remain enabled in the Advanced Sharing settings.
If the issue persists, you may want to confirm whether SMB 1.0 is required in your environment (some older devices depend on it) and temporarily enable it for testing, though we advise using it only when necessary for security reasons. I also suggest installing the latest cumulative update, as Microsoft often releases quick follow ups that address network stack regressions.
Please "accept the answer" so that it could be spread further to those in need too. If not, is there anything I can help you with? Please let me know.